Influence of Global Warming on Extreme Sea Level Events Along European Coasts

Coastal sea level extremes are among the potentially most hazardous events for the densely populated coastal regions. Changes in extreme sea levels, combined with rising mean sea level, increase coastal vulnerability, and will continue to do so in the future. It is thus necessary to understand and quantify the role of global warming in the likelihood and intensity of extreme sea levels. In this study, we aim at testing whether the probability of extreme sea levels has changed in any way due to global warming. To do so, we analyse annual sea level maxima of a large ensemble of hydrodynamic simulations along the European coasts forced with the outputs of state-of-the-art climate models, simulating a total of nearly 1800 years of data that are representative of the climate of the past 6 decades, as well as 2500 years of data that are representative of the pre-industrial climate. The data have been bias-corrected to improve their reliability and accuracy in representing local sea level variations. We rely on the largely extended dataset to compute the Fraction of Attributable Risk (FAR) for different sets of sea level extremes along the entire European coastline. The results reveal that present-day regional climate conditions are altering the probability of likelihood of extreme sea levels along a large fraction of the European coastlines.